Process for breaking petroleum emulsions



Patented Jan. 27, 1953 PROCESS FOR BREAKING PETROLEUM EMULSIONS MelvinDe Groote, University City, Mo., assignor to Petrolite Corporation, acorporation of Delaware No Drawing. Application May 14, 1951, Serial N0.226,306

11 Claims.

The present invention is a continuation-inpart of my copendingapplications Serial Nos. 104,801 filed July 14, 1949 (now Patent2,552,528, granted May 15, 1951), 109,619 filed August 10, 1949 (nowPatent 2,552,531, granted May 15, 1951), and 107,381 filed July 28, 1949(now Patent 2,552,530 granted May 15, 1951). This invention relates topetroleum emulsions of the water-in-oil type that are commonly referredto as cut oil, roily oil, emulsified oil, etc., and which com-prise finedroplets of naturally-occurring waters or brines dispersed in a more orless permanent state throughout the oil which constitutes the continuousphase of the emulsion.

One object of my invention is to provide a novel process for breaking orresolving emulsions of the kind referred to. Another object of myinvention is to provide an economical and rapid process for separatingemulsions which have been prepared under controlled conditions frommineral oil, such as crude oil and relatively soft waters or weakbrines. Controlled emulsifioation and subsequent demulsification underthe conditions just mentioned are of significantvalue in removingimpurities, particularly inorganic salts from pipeline oil.

Demulsification as contemplated in the present application includes thepreventive step of commingling the demulsifier with the aqueouscomponent which would or might subsequently become either phase of theemulsion, in absence of such precautionary measure. Similarly, suchdemulsifier may be mixed with the hydrocarbon component.

The demulsifying agent employed in the present process is a fractionalester obtained from a polycarboxy acid and a polyhydroxylated materialobtained by the oxypropylation of a polyamino reactant.

More specifically the present process involves the use of a demulsifyingagent which is an acidic acylation product of a polycarboxy acid with acompound derived in turn by the oxypropylation of triethylenetetramineor an equivalent tetramine as hereinafter specified, having a pluralityof terminal hydroxyl radicals or the equivalent, i. e., labile hydrogenatoms susceptible to oxyalkylation.

The most suitable raw material is triethylenetetramine or such producttreated with several moles of ethylene oxide or glycide, or acombination of the two, particularly triethylenetetramine treated withone to five, six or seven moles of ethylene oxide.

The initial tetramine must be characterized by (a) Having 4 aminonitrogen atoms and preferably all being basic;

(1)) Free from any radical having 8 or more carbon atoms in anuninterrupted group;

(0) Must be water-soluble;

(d) Have a plurality of reactive hydrogen atoms, preferably at least 3,4 or 5; and

(e) Must have a molecular weight of not over 800.

The oxypropylated derivatives of such tetramines, which are reacted withpolycarboxy acids to produce compounds used in accordance with thepresent invention, must have a molecular weight within the range of 2500to 30,000, must be water-insoluble and kerosene-soluble, must have aratio of propylene oxide to reactive hydrogen atoms of the tetramine inthe range of '7 to 70, and the tetramino compound must repre sent notmore than 20% by weight of the oxypropylated product, the ratios andmolecular Weights specified being on a statistical basis and based on anassumption of complete reaction between the tetramine and thepropyleneoxide.

When forming the acylation products, the polycarboxy acid is used in amolar ratio of one mole of polycarboxy acid for each reactive hydrogenof the oxypropylated tetramino compound.

For reasons which will be pointed out, I believe the products areessentially fractional esters, but may to some extent have an amidestructure and in addition, because of the fact that one or more of thenitrogen atoms are advantageously basic, may also be in the form ofester salts. For this reason they are referred to above as acylationproducts, and for this reason in the claims the products are referred toas being selected from the class consisting of acidic fractional esters,acidic ester salts and acidic amido derivatives.

Needless to say, the most readily available reactant, to wit,triethylenetetramine has 6 reactive hydrogen atoms and this would betrue after treatment with ethylene oxide, for instance, 6 moles ofethylene oxide. However, reaction with glycide would provide as many as12 reactive hydrogen atoms provided the molal ratio was still the sameas before, to wit, 6 moles of glycide per mole of tetramine. On theother hand, if triethylenetetramine were treated with an alkylatingagent so as to introduce an alkyl radical such as methyl, ethyl, propyl,butyl, hexyl, heptyl, or the like, or an aryl radical such as a phenylradical, then and in that event the number of reactive hydrogen atomsmight be decreased to as few as two or three and still be acceptable forthe instant purpose. If an alkyl radical or an alicyclic radical, suchas a cyclohexyl radical, or an alkyl aryl radical such as a benzylradical, were introduced the basicity of the nitrogen atom would not bematerially affected. However, the introduction of a phenyl radicalwould, of course, markedly affect the basicity of the nitrogen atom. Forobvious reasons my choice is as follows:

(a) The use of triethylenetetramine rather than any substitutedtriethylenetetramine as described;

(b) The use of triethylenetetramine after treatment with 1 to 6 moles ofethylene oxide although a modestly increased amount of ethylene oxidecan be used in light of what is said hereinafter, or

(c) The use of a derivative obtained from triethylenetetramine afterreaction with glycide, or a mixture of ethylene oxide and glycide.

Since reaction of triethylenetetramine with propylene oxide isinvariably involved and since this oxyalkylation step was substantiallythe same as the use of ethylene oxide or glycide, for purpose of brevityfurther reference will be made to triethylenetetramine as illustratingthe procedure regardless of what particular reactant is selected. It isnot necessary to point out, of course, that the substitutedtriethylenetetramines, i. e., those where an alkyl radical, alicyclicradical, aryl-alkyl, or aryl group has been introduced can be subjectedsimilarly to reaction With ethylene oxide, glycide, or a combination ofthe two.

I also want to point out it is immaterial whether the initialoxypropylation step involves hydrogen attached to oxygen or hydrogenattached to nitrogen. The essential requirement is that it be a labileor reactive hydrogen atom. Any substituent radical present must, ofcourse, have less than 8 uninterrupted carbon atoms in a single group.

Reference to the products as fractional esters may be, and probablywould be, an over-simplification for reasons which are obvious onfurther examination. It is pointed out subsequently that prior toesterification the alkaline catalyst can be removed by addition ofhydrochloric acid. Actually the amount of hydrochloric acid added isusually sumcient and one can deliberately employ enough acid, not onlyto neutralize the alkaline catalyst but also to neutralize the aminonitrogen atom or convert it into a salt. Stated another way, a trivalentnitrogen atom is converted into a pentavalent nitrogen atom, i. e., achange involving an electrovalency indicated as follows:

wherein HX represents any strong acid or fairly strong acid such ashydrochloric acid, nitric acid, sulfuric acid, a sulphonic acid, etc. inwhich I-I represents the acidic hydrogen atom and X rep resents theanion. Without attempting to complicate the subsequent descriptionfurther it is obvious then that one might have esters or one mightconvert the esters into ester salts as described. Likewise anotherpossibility is that under certain conditions one could obtain amides.The explanation of this latter fact resides in this observation. In thecase of an amide, such as acetamide, there is always a question as towhether or not oxypropylation involves both amido hydrogen atoms so asto obtain a hundred per cent yield of the dihydroxylated compound. Thereis some evidence to at least some degre that a monohydroxylated compoundis obtained under some circumstances with one amido hydrogen atomremaining without change.

Another explanation which has sometimes appeared in the oxypropylationof nitrongen-containing compounds particularly such as acetamide, isthat the molecule appears to decompose under conditions of analysis andunsaturation seems to appear simultaneously. One suggestion has beenthat one hydroxyl is lost by dehydration and that this ultimately causesa break in the molecule in such a way that two new hydroxyls are formed.This is shown after a fashion in a highly idealized manner in thefollowing way:

In the above formulas the large X is obviously not intended to signifyanything except the central part of a large molecule, whereas, as far asa speculative explanation is concerned, one need only consider theterminal radicals, as shown. Such suggestion is of interest only becauseit may be a possible explanation of how an increase in hydroxyl valuedoes take place which could be interpreted as a decrease in molecularweight. This matter is considered subsequently in the final paragraphsof Part 2. This same situation seems to apply in the oxypropylation ofat least some polyalkylene amines and thus is of significance in theinstant situation.

In the case of higher polyamines there is evidence that all theavailable hydrogen atoms are not necessarily attacked, at least undercomparatively modest oxypropylation conditions, particularly whenoxypropylation proceeds at low temperature as herein described, forinstance, about the boiling point of water. For instance, in the case ofdiethylene triamine there is some evidence that one terminal hydrogenatom only in each of the two end groups is first attacked by propyleneoxide and then the hydrogen atom attached to the central nitrogen atomis attacked. It is quite possible that three long propylene oxide chainsare built up before the two remaining hydrogens are attacked and perhapsnot attacked at all. This, of course, depends on the conditions ofoxypropylation. However, analytical procedure is not entirelysatisfactory in some instances in diiferentiating between a reactivehydrogen atom attached to nitrogen and a reactive hydrogen atom attachedto oxygen.

In the case of triethylenetetramine the same situation seems to follow.One hydrogen atom on the two terminal groups is first attacked and thenthe two hydrogen atoms on the two intermediate nitrogen atoms. Thus fourchains tend to build up and perhaps finally, if at all, the remainingtwo hydrogen atoms attached to the two terminal groups are attacked. Inthe case of tetraethylenepentamine the same approach seems to hold. Onehydrogen atom on each of the terminal groups is attacked first, then thethree hydrogen atoms attached to the three intermediate nitrogen atoms,and then finally, if at all depending on conditions of oxypropylation,the two remaining terminal hydrogen atoms are attacked.

If this is the case it is purely a matter of speculation at the momentbecause apparently there are no data which determine the matter com--pletely under all conditions of manufacture, and one has a situationsomewhat comparable to the acylation of monoethanolamine ordiethanolamine, i. e., acylation can take place involving either thehydrogen atom attached to oxygen or the hydrogen atom attached tonitrogen.

As far as the herein described compounds are concerned it would beabsolutely immaterial except that one would have in part a compoundwhich might be the fractional ester and might also represent an amide inwhich only one carboxyl radical of a polycarboxylated reactant wasinvolved. By and large, it is believed that the materials obtained areobviously fractional esters, for reasons which are apparent in light ofwhat has been said and in light of what appears hereinafter.

For convenience what is said hereafter will be divided into four parts:

Part gl is concerned with the preparation of the oxypropylationderivative of triethylene tetramine or equivalent initial reactants;

Part2 is concerned with the preparation of the esters from theoxypropylated derivatives;

Partr-3 is concerned with the nature of the 'oxypropylation derivativesinsofar that such cogeneric mixture is invariably obtained, and

Part- 4 is concerned with the use of the products herein described asdemulsifiers for break ing water-in-oil emulsions.

PART 1 Oxypropylations are conducted under a wide 1 variety: ofconditions, not only in regard to presence or absence of catalyst, andthe kind of catalyst, but also in regard to the time of reaction,temperature of reaction, speed of reaction, pressure during reaction,etc. For instance; oxyalkylations can be conducted at temperatures up toapproximately 200 C. with pressures in about the same range up to about200 pounds per square inch. They can be conducted also at temperaturesapproximating the boiling point of water or slightly above, as forexample 95 to" 120 0. Under such circumstances the pressure will be lessthan 30 pounds per square inch .unless some special procedure isemployed 8.8.113, sometimes the case, to wit, keeping an atmospliere ofinert gas such as nitrogen in thevesselj during the reaction. Suchlow-temperature-low reaction rate oxypropylations have been describedvery completely in U. S. Patent No. 2,-3.48,664, to H. R. Fife, et al.,dated September '7, 1948.33 Low temperature, low pressureoxypropylations are particularly desirable where the compound beingsubjected to oxypropylation contains one, two or three points ofreaction only,

such as monohydric alcohols, glycols and triols. I

The initial reactants in the instant application contain at least 2reactive hydrogens and for this reason there is possibly less advantagein using low temperature oxypropylation rather than high temperatureoxypropylation. However, the re- 6 actions do not go too slowly and thisparticular procedure was used in the subsequent examples.

Since low pressure-low temperature-low-reaction-speed oxypropylationsrequire considerable time, for instance, 1 to 7 days of 24 hours each tocomplete the reaction they are conducted as a rule whether on alaboratory scale, pilot plant scale, or large scale, so as to operateautomatically. The prior figure of seven days applies especially tolarge-scale operations. I have used conventional equipment with twoadded automatic features; (a) a solenoid controlled valve which shutsofi the propylene oxide in event that the temperature gets outside apredetermined and set range, for instance, to C., and (b) anothersolenoid valve which shuts off the propylene oxide (or for that matterethylene oxide if it is being used) if the pressure gets beyond apredetermined range, such as 25 to 35 pounds. Otherwise, the equipmentis substantially the same as is commonly employed for this purpose wherethe pressure of reaction is higher, speed of reaction is higher, andtime of reaction is much shorter. In such instances such automaticcontrols are not necessarily used.

Thus, in preparing the various examples I have found it particularlyadvantageous to use laboratory equipment or pilot plant which isdesigned to permit continuous oxyalkylation whether it beoxypropyl-ation or oxyethylation. With certain obvious changes theequipment can be used also to permit oxyalkylation involving the use ofglycide where no pressure is involved except the vapor pressure of asolvent, if any, which may have been used as a diluent.

As previously pointed out the method of using propylene oxide is thesame as ethylene oxide. This point is emphasized only for the reasonthat the apparatus is so designed and constructed as to use eitheroxide.

The oxypropylation procedure employed in the preparation of theoxyalkylated derivatives has been uniformly the same, particularly inlight of the fact that a continuous automaticallycontrolled procedurewas employed. In this procedure the autoclave was a conventionalautoclave made of stainless steel and having a capacity of approximately15 gallons and a working pressure of one thousand pounds gauge pressure.This pressure obviously is far beyond any requirement as far aspropylene oxide goes unless there is a reaction of explosive violenceinvolved due to accident. The autoclave was equipped with theconventional devices and openings, such as the variablespeed stirreroperating at speeds from 50 R. P. M. to 500 R. P. M.; thermometer welland thermocouple for mechanical thermometer; emptying outlet, pressuregauge, manual vent line; charge hole for initial reactants; at least oneconnection for introducing the alkylene oxide, such as propylene oxideor ethylene oxide, to the bottom of the autoclave; along with suitabledevices for both cooling and heating the autoclave, such as a coolingjacket, and, preferably, coils in addition thereto, with the jacket soarranged that it is suitable for heating with steam or cooling withwater and further equipped with electrical heating devices. Suchautoclaves are, of course, in essence small-scale replicas of the usualconventional autoclave used in oxyalkylation procedures. In someinstances in exploratory preparations an autoclave having a smallercapacity, for instance, approximately 3 liters in one case and about 1%gallons in another case, was used.

Continuous operation, or substantially continuous operation, wasachieved by the use of a separate container in hold the alkylene oxidebeing employed, particularly propylene oxide. In conjunction with thesmaller autoclaves, the container consists essentially of a laboratorybomb having a capacity of about one-half gallon, or somewhat in excessthereof. In some instances a larger bomb was used, to wit, one having acapacity of about one gallon. This bomb was equipped, also, with aninlet for charging, and an eductor tube going to the bottom of thecontainer so as to permit discharging of alkylene oxide in the liquidphase to the autoclave. A bomb having a capacity of about 60 pounds wasused in connection with the 15-gallon autoclave. Other conventionalequipment consists, of course, of the rupture disc, pressure gauge,sight feed glass, thermometer connection for nitrogen for pressuringbomb, etc. The bomb was placed on a scale during use. The connectionsbetween the bomb and the autoclave were flexible stainless steel hose ortubing so that continuous weighings could be made without breaking ormaking any connections. This applies also to the nitrogen line, whichwas used to pressure the bomb reservoir. To the extent that it wasrequired, any other usual conventional procedure or addi tion whichprovided greater safety was used, of course, such as safety glassprotective screens, etc.

Attention is directed again to what hasbeen said previously in regard toautomatic controls which shut off the propylene oxide in eventtemperature of reaction passes out of the predetermined range or ifpressure in the autoclave passes out of predetermined range.

With this particular arrangement practically all oxypropylations becomeuniform in that the reaction temperature was held within a few degreesof any selected point, for instance, if 105 C. was selected as theoperating temperature the maximum point would be at the most 110 C. or112 C., and the lower point would be 95 or possibly 98 C. Similarly, thepressure was held at approximately 30 pounds maximum within a -poundvariation one way or the other, but might drop to practically zero,especially where no solvent such as xylene is employed. The speed ofreaction was comparatively slow under such conditions as compared withoxyalkylations at 200 C. Numerous reactions were conducted in which thetime varied from one day (24 hours) up to three days (72 hours), forcompletion of the final member of a series. In some instances thereaction may take place in considerably less time, i. e., 24 hours orless, as far as a partial oxypropylation is concerned. The minimum timerecorded was about a 6-hour period in a single step. Reactions indicatedas being complete in 7 or 8 hours may have been complete in a lesserperiod of time in light of the automatic equipment employed. In theaddition of propylene oxide, in the autoclave equipment as far aspossible the valves were set so all the propylene oxide if fedcontinuously would be added at a rate so that the predetermined amountwould react within the first 5 hours of the 8-hour period or two-thirdsof any shorter period. This meant that if the reaction was interruptedautomatically for a period of time for pressure to drop or temperatureto drop the predetermined amount of oxide would still be added in mostinstances well within the predetermined time period. Sometimes where theaddition was a comparatively small amount 8 in a 8-hour period therewould be anunquestionable speeding up of the reaction, by simplyrepeating the example and using 4, 5 or 6 hours instead of 8 hours. 7 1

When operating at a comparatively high temperature, for instances,between 150 to 200 C.-, an unreacted alkylene oxide such as propyleneoxide, makes its presence felt in the increase in pressure or theconsistency of a high pressure; However, at a low enough temperature itmay happen that the propylene oxide goes in as .a liquid. If so, and ifit remains unreacted there is, of course, an inherent danger andappropriate steps must be taken to safeguard against this pos sibility;if need be a sample must be withdrawn and examined for unreactedpropylene oxide. One obvious procedure, of course, is to oxypropylate ata modestly higher temperature, for instance, at to C. Unreacted'oxide atfects determination of the acetyl or hydroxyl value of the hydroxylatedcompound obtained.

The higher the molecular weight ofthe com pound, i. e., towards thelatter stages of reaction, the longer the time required to add a givenamount of oxide. One possible explanation is that the molecule, beinglarger, the-opportunity for random reaction is decreased. Inversely, thelower the molecular weight the faster the reaction takes place. For thisreason, sometimes at least, increasing the concentration of the catalystdoes not appreciably speed up the reaction, particularly when theproduct subjected to'oxyalkylation has a comparatively high molecularweight. However, as has been pointed out previ ously, operating at a lowpressure and a low tern: perature even in large scale operations as muchas a week or ten days time may lapse toobtain some of the highermolecular weight derivatives from monohydric or dihydric materials.- Ina number of operations the counterbalance scale or dial scale holdingthe propylen oxide bomb was so set that when the predetermined amount ofpropylene oxide had passed into the reaction the scale movement througha time operating device was set for either one to two hours so thatreaction continued for 1 to 3 hours after the final addition of the lastpropylene oxide and thereafter the operation was shut down. Thisparticular device is particularly suitable for use on larger equipmentthan laboratory size autoclaves, to wit, on semi-pilot plant or pilotplant size, as well as on large scale size. This final stir-; ringperiod is intended to avoid the presence of unreacted oxide.

In this sort of operation, of course, the temperature range wascontrolled automatically by; either use of cooling water, steam, orelectrical heat, so as to raise or lowerthe temperature; The pressuringof the propylene oxide into the reaction vessel was also automaticinsofar that the feed stream was set for a slow continuous run which wasshut off in case the pressure passed a predetermined point as previouslyset out. All the points of design, construction, etc., were conventionalincluding the gauges, check valves and entire equipment. As far as I amaware at least two firms, and possibly three, specialize in autoclaveequipment such as I have employed in the laboratory, and are prepared tofurnish equipment of this same kind. Similarly pilot plant equipment isavailable. This point is simply made as a precaution in the direction ofsafety. Oxyalkylations, particularly involving ethylene oxide, glycide,propylene oxide, etc., should not be com ducted except in equipmentspecially designed for the purpose.

It is to be noted in the present instance one may or may not have basicnitrogen atoms present. For example, if a phenyl radical is attached toeach nitrogen atom the initial tetramine is substantially nonbasic.However, if one employs triethylenetetramine there are present fourbasic nitrogen atoms and thus the addition of an alkaline catalyst canbe eliminated in the early stages of oxypropylation or oxyethylation.This is illustrated subsequently by the fact that oxypropylation waspermitted to go through the first stage without the addition of alkalinecatalyst.

Example 1a The particular autoclave employed was one with a capacity ofapproximately 15 gallons or on the average of about 125 pounds ofreaction mass. The speed of the stirrer could be varied from 150 to 350R. P. M. The initial charge was 12.62 pounds of triethylenetetramine. Inthe initial charge no catalyst was added. The reaction pot was flushedout with nitrogen, the autoclave sealed and the automatic devicesadjusted and set for injecting 71.75 pounds of propylene oxide in a5-hour period. The pressure regulator was set for a maximum of 35-37pounds per square inch. However, in this particular step and in allsucceeding steps the pressure never got over 33 pounds per square inch.In fact, this meant that the bulk of the reaction could take place anddid take place at an appreciably lower pressure. This comparatively lowpressure was the result of the fact that the reactant per se was basic.The propylene oxide was added at a rate of about 17 /2 pounds per hourand at a comparatively moderate temperature, to wit, 250255 F.(moderately higher than the boiling point of water). The initialintroduction of propylene oxide did not start until the heating deviceshad raised the temperature to approximately 245 F. At the completion ofthe reaction a sample was taken and oxypropylation proceeded as inExample 2a, immediately following.

Example 2a 50.87 pounds of the reaction mass equivalent to 7.60 poundsof the polyamine and 43.27 pounds of propylene oxide, and identified asExample 1a, preceding, were permitted to stay in the reaction vessel andthere was added .75 pound of caustic soda. The mixture was then reactedwith 43.25 pounds of propylene oxide. The oxypropylation was conductedin substantially the same manner in regard to temperature and pressureas in Example la, preceding. The time period in this case was 6 hours.The propylene oxide was added at approximately 9 to 10 pounds per hour.At the end of the reaction period part of the sample was withdrawn andoxypropylation continued as described in Example 3a, following.

Example 3a 51.12 pounds of the reaction mass identified as Example 2a,preceding, and equivalent to 4.10 pounds of polyamine, 46.62 pounds ofpropylene oxide, and .40 pound of caustic soda, were permitted to stayin the reaction vessel. 43 pounds of propylene oxide were introduced ina 6-hour period. No additional catalyst was added. The conditions ofreaction as far as temperature and pressure were concerned weresubstantially the same as in Example 1a, preceding. The propylene oxidewas added at the rate of about 10 to 11 pounds per hour. At thecompletion of the reaction part of the reaction mass was withdrawn andthe remainder subjected to further oxypropylation as described inExample 4a, immediately following.

Example 4a 47.62 pounds of the reaction mass identified as Example 3a,preceding, and equivalent to 2.07 pounds of polyamine, 45.35 pounds ofpropylene oxide and .20 pound of caustic soda, were permitted to stay inthe autoclave. No additional catalyst was introduced. Conditions inregard to temperature and pressure were substantially the same as inExample 1a, preceding. In this instance the oxide was added in 7 hours.The amount of oxide added was 32.25 pounds. The addition was at the rateof approximately 6 pounds per hour. At the end of the reaction periodpart of the reaction mass was withdrawn and the remainder of thereaction mass subjected to further oxypropylation as described inExample 5a, following.

Example 5a 59.87 pounds of reaction mass identified as Example la,preceding, and equivalent to 1.57 pounds of polyamine, 58.15 pounds ofpropylene oxide, and .15 pound of caustic soda, were permitted to stayin the autoclave. No additional catalyst was added. This mass wassubjected to reaction with 20 pounds of propylene oxide. The conditionsof reaction were substantially the same as described in Example lot asfar as temperature and pressure were concerned. The period required toadd the oxide was 9 hours. The oxide was added at the rate of 2 poundsper hour.

In other similar series I have used a catalyst at the very beginning,adding some caustic soda and particularly modestly more than aboveindicated; for instance, in a similar experiment I added initially 1.15pounds of caustic soda andcontinued oxypropylation to give a molecularweight range as high as 9,000 to 10,000 and higher with a hydroxylmolecular weight between 5,000 and 6,000 or higher. These products soobtained at the higher molecular weight range had the samecharacteristics as far as solubility goes, as in Examples 4a and 5a,described in the paragraph following Table 1.

What has been said herein is presented in tabular form in Table 1immediately following with some added information as to molecular weightand as to solubility of the reaction product in water, xylene andkerosene.

TABLE 1 Composition Before Composition at End M W b Max Max Ex. H XTenn; Pres Time, No. Amine Oxide Gata- Theo. Amine Oxide Cata- D O lbsHrs.

Amt, Amt, lyst, M01. Amt, Amt, lyst, min sq in lbs. lbs. lbs. Wt. lbs.lbs. lbs.

la 12. 62 972 12. 62 71. 75 1. 852 225-230 -37 5 2a 7. 60 43. 27 75 1,805 7. 60 86. 52 75 1, 284 250-255 35-37 6 3a.. 4. 10 46. 62 3, 335 4.10 89. 62 40 2, 280 250-255 35-37 6 4a. 2.07 45. 35 20 5, 625 2.07 77.20 3, 400 250-255 35-37 7 5a. 1. 57 58. 15 l5 7, 395 l. 57 78. 15 .15 4,370 250-255 35-37 9 Examples 1a and 2a were both soluble in water,soluble in xylene, and insoluble in kerosene; Example 3a wasemulsifiable to insoluble in water, but soluble in xylene, anddispersible to insoluble in kerosene; and Examples 4a. and 50. wereinsoluble in water, but soluble in both xylene and kerosene.

The final product, i. e., at the end of the oxypropylation step, was asomewhat viscous, pale amber to dark reddish amber colored fluid whichwas water-insoluble. This is characteristic of all the products obtainedfrom the tetramine products herein described. Needless to say if someethylene oxide radicals were introduced into the initial raw materialthe initial product is more water-soluble and one must go to highermolecular weights to produce water-insolubility and kerosene-solubility,for instance, molecular weights such as 10,000 to 12,000 or more on atheoretical basis, and 6,000 to 8,000 or 10,000 on a hydroxyl molecularweight basis. If, however, the initial tetramine compound is treatedwith one or more or perhaps several moles of butylene oxide then thereverse effect is obtained and it takes less propylene oxide to producewater-ins-olubil-ity and kerosene-solubility. These products were, ofcourse, alkaline due in part to the residual caustic soda employed. Thiswould also be the case if sodium methylate were used as a catalyst.

Speaking of insolubility in water or solubility in kerosene suchsolubility test can be made simply by shaking small amounts of thematerials in a test tube with water, for instance, using 1% to 5%approximately based on the amount of water present.

Needless to say, there is no complete conversion of propylene oxide intothe desired hydroxylated compounds. This is indicated by the fact thatthe theoretical molecular weight based on a statistical average isgreater than the molecular weight calculated by usual methods on basisof acetyl or hydroxyl value. Actually, there is no completelysatisfactory method for determining molecular weights of these types ofcompounds with a high degree of accuracy when the molecular weightsexceed 2,000. In some instances the acetyl value or hydroxyl valueserves as satisfactorily as an index to the molecular weight as anyother procedure, subject to the above limitations, and especially in thehigher molecular weight range. If any difficulty is encountered in themanufacture of the esters as described in Part 2 the stoichiometricalamount of acid or acid compound should be taken which corresponds to theindicated acetyl or hydroxyl value. This matter has been discussed inthe literature and is a matter of common knowledge and requires nofurther elaboration. In fact, it is illustrated by some of the examplesappearing in the patent previously mentioned.

PART 2 As previously pointed out the present invention is concerned withacidic esters obtained from the oxypropylated derivatives described inPart 1, immediately preceding, and polycarboxy acids, particularlytricarboxy acids like citric and dicarboxy acids such as adipic acid,phthalic acid, or anhydride, succinic acid, diglycollic acid, sebacicacid, azelaic acid, aconitic acid, maleic acid or anhydride, citraconicacid or anhydride, maleic acid or anhydride adducts as obtained by theDiels-Alder reaction from products such as maleic anhydride, andcyclopentadiene. Such acids should be heat stable so they are notdecomposed during esteriflcation. They may contain as many as 36 carbonatoms as, for example, the acids obtained by dimerization of unsaturatedfatty acids, unsaturated monocar boxy fatty acids, or unsaturatedmonocarboxy acids having 18 carbon atoms. Reference to the acid in thehereto appended claims obviously includes the anhydrides or any otherobvious equivalents. My preference, however, is to use polycarboxy acidshaving not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) frompolycarboxy acids and glycols or other hydroxylated compounds is wellknown. In the present instance the hydroxylated compounds obtained asdescribed in Part 1, preceding, contain nitrogen atoms which may or maynot be basic. Thus, it is probable particularly where there is a basicnitrogen atom present that salts may be formed but in any event underconditions described the salt is converted into an ester. This iscomparable to similar reactions involving the esterification oftriethanolamine. Possibly the addition of an acid such as hydrochloricacid if employed for elimination of the basic catalyst also combineswith the basic nitrogen present to form a salt. In any event, however,such procedure does not afiect conventional esterification procedure asdescribed herein.

Needless to say, various compounds may be used such as the low molalester, the anhydride, the acyl chloride, etc. However, for purpose ofeconomy it is customary to use either the acid or the anhydride. Aconventional procedure is employed. On a laboratory scale one can employa resin pot of the kind described in U. S. Patent No. 2,499,370, datedMarch 7, 1950 to De Groote and Keiser, and particularly with one moreopening' to permit the use of a porous spreader if hydrochloric acid gasis to be used as a catalyst. Such device or absorption spreader consistsof minute alunduin thimbles which are connected to a glass tube. One canadd a sulfonic acid such as para-toluene sulfonic acid as a catalyst.There is some objection to this because in some instances there is someevidence that this acid catalyst tends to decompose or rearrange theoxypropylated compounds, and particularly likely to do so if theesterifieation temperature is too high. In the case of polycarboxy acidssuch as diglycollic acid, which is strongly acidic there is no need toadd any catalyst. The use of hydrochloric acid gas has one advantageover para-toluene sulfonic acid and that is that at the end of thereaction it can be removed by flushing out with nitrogen. whereas thereis no reasonably convenient means available of removing the paratoluenesulfonic acid or other sulfonic acid employed. If hydrochloric acid isemployed one need only pass the gas through at an exceedingly slow rateso as to keep the reaction mass acidic. Only a trace of acid need bepresent. I have employed hydrochloric acid gas or the aqueous aciditself to eliminate the initial basic material. My preference, however,is to use no catalyst whatsoever.

The products obtained in Part 1 preceding may contain a basic catalyst.As a general procedure I have added an amount of half-concentratedhydrochloric acid considerably in excess of what is required toneutralize the residual catalyst. The mixture is shaken thoroughly andallowed to stand overnight. It is then filtered and refluxed with thexylene present until the water can be separated in a phase-separatingtrap. As

soon as the product is substantially free from water the distillationstops. This preliminary step can be carried out in the flask to be usedfor esterification. If there is any further deposition of sodiumchloride during the reflux stage needless to say a second filtration maybe required. In any event the neutral or slightly acidic solution of theoxpyropylated derivatives described inPart l is then diluted furtherwith sufficient xylene, decalin, petroleum solvent, or the like, so thatone has obtained approximately a 40% solution. To this solution there isadded a polycarboxylated reactant as previously described, such asphthalic anhydride, succinic acid or anhydride, diglycollic acid, etc.The mixture is refluxed until esterification is complete as indicated byelimination of water or drop in carboxyl value. Needless to say, if oneproduces a half-ester from an ahydride such as phthalic anhydride, nowater is eliminated. However, if it is obtained from diglycollic acid,for example, water is eliminated. All such procedures are conventionaland have been so thoroughly described in the literature that furtherconsideration will be limited to a few examples and a comprehensivetable.

Other procedures for eliminating the basic residual catalyst, if any,can be employed. For example, the oxyalkylation can be conducted inabsence of a solvent or the solvent removed after oxypropylation. Suchoxypropylation end product can then be acidified with just enoughconcentrated hydrochloric acid or just neutralize the residual basiccatalyst. To this product one can then add a small amount of anhydroussodium sulfate (sufficient in quantity to take up any water that ispresent) and then subject the mass to centrifugal force so as toeliminate the hydrated sodium sulfate and probably the sodium chlorideformed. The clear, dark-reddish to amber liquid so obtained may containa small amount of sodium sulfate or sodium chloride but, in any event,is perfectly acceptable for esterification in the manner described.

It is to be pointed out that the products here described are notpolyesters in the sense that there is a plurality of both tetraminoradicals and acid radicals; the product is characterized by having onlyone tetramino radical.

In some instances and, in fact, in many instances I have found that inspite of the dehydration methods employed above that a mere trace ofwater still comes through and that this mere trace of water certainlyinterferes with the acetyl or hydroxyl value determination, at leastwhen a number of conventional procedures are used and may retardesterification, particularly where there is no sulfonic acid orhydrochloric acid present as a catalyst. ferred to use the followingprocedure: I have employed about 200 grams of the polyhydroxylatedcompound as described in Part 1, preceding; I have added about 60 gramsof benzene, and then refluxed this mixture in the glass resin pot usinga phase-separating trap until the benzene carried out all the waterpresent as water of solution or the equivalent. Ordinarily thisrefluxing temperature is apt to be in the neighborhood of 130 topossibly 150 C. When all this water or moisture has been removed I alsowithdraw approximately 20 grams or a little less benzen and then add therequired amount of thecarboxy reactant and also about 150 grams ofafhighboiling aromatic petroleum solvent. These solvents are sold byvarious oil refineries and, as

Therefore, I have pre- :14 far as solvent effect act as if they werealmost completely aromatic in character. Typical distillation data inthe particular type I have employed and found very satisfactory is thefollow- I. B. P., 142 C. ml., 242 C. 5 ml., 200 C. ml., 244 C. 10 ml.,209 C. ml., 248 C. 15 ml., 215 C. ml., 252 C. 20 ml., 216 C. ml., 252 C.25 ml., 220 C. ml., 260 C. 30 ml., 225 C. ml., 264 C. 35 ml., 230 C.ml., 270 C. 40 ml., 234 C. ml., 280 C. 45 ml., 237 C. ml., 307 C.

After this material is added, refluxing is con tinued and, of course, isat a higher temperature, to wit, about to C. If the carboxy reactant isan anhydride needless to say no water of reaction appears; if thecarboxy reactant is an acid water of reaction should appear and shouldbe eliminated at the above reaction temperature. If it is not eliminatedI simply separate out another 10 or 20 cc. of benzene by means of thephase-separating trap and thus raise the temperature to or C., or evento 200 C., if need be. My preference is not to go above 200 C.

The use of such solvent is extremely satisfactory provided one does notattempt to remove the solvent subsequently except by vacuum distillationand provided there is no objection to a little residue. Actually, whenthese materials are used for a purpose such as demulsification thesolvent might just as well be allowed to remain. If the solvent is to beremoved by distillation, and par: ticularly vacuum distillation, thenthe high boil-. ing aromatic petroleum solvent might well be replaced bysome more expensive solvent, such as decalin or an alkylated decalinwhich has a rather definite or close range boiling point. The removal ofthe solvent, of course, is purely a conventional procedure and requiresno elaboration.

In a number of the examples the #7-3 solvent was entirely satisfactory,as, for example, in Examples 201) through 30b. This is particularly thecase where the oxypropylated derivative showed decreasedwater-solubility. However, when the products showed significantwater-solubility the difficulty arose that at the end of theesterification reaction the solvent and resultant or reaction mass wasnot homogeneous. Thus, in Examples 1b, 2b, 4b and 6b the solvent isshown as a mixture of #7-3 solvent and methanol. Approximatelytwo-thirds the solvent indicated was solvent #7-3. When all the waterhad been eliminated methanol equal to approximately onethird thesubsequent mixture was added so as to give a single phase system. Inother examples, for instance, Examples 35 and 5b, methanol itself wasnot entirely satisfactory so that instead of adding one-third methanol(in reality 50% based on the solvent #7-3 present) there wasadded anequal weight of methanol and Diethyl Carbitol which is diethyleneglycoldiethylether. Thus, the actual solvent consisted of approximatelytwo-thirds solvent #7-3, one-sixth methanol, and one-sixthdiethyleneglycol diethylether. In Examples 7b through 1% it was foundthat xylene seemed to be the most suitable to employ. Diethyl Carbitolis a trade name for diethyleneglycol diethylether. These solventproportions can be varied somewhat-without change, the object beingmerely to eliminate the water in the pres- 16 manner that is acceptable,attention should be directed to the following details: (a) Recheck thehydroxyl or acetyl value of the oxypropylated derivative and use astoichiometrioally equivalent amount of acid; (b) if the reaction doesnot proceed with reasonable speed either raise the temperature indicatedor else extend the period of time up to 12 or 16 hours if need be; (c)if necessary, use /270 of paratoluene sulfonic acid or some other acidas a catalyst provided that the hydroxylatecl compound is not basic; (d)if the esterification does not Produce a clear product a check should bemade to see if an inorganic TABLE 2 Theo. M01. Amt. t NEX. 2 Eff dHylAgual BWtd g? Pglyo. of roxy yase car oxy EAcid dlrigz-y Vague 3 1 A t 165231 Polycarboxy Reactant ster o a ue 0 ma an mPd C H. c. H. v. (gr-7)(grs) la 976 230 263 852 185 Diglycolic Acid 117. 5 la 976 230 263 852182 Oxalic Acid 108 1a 976 230 263 852 192 lVIaleic Anhydride 87. 6 la976 230 263 852 188 Phthalic Anhydride. 131 la 976 230 263 852 183Aconitio Acid 150 la 976 230 263 852 180 Citraconic Anhyd 94. 2 2a 1,805 124 174. 5 l, 284 198 Diglycolic Acid. 82. 6 2a 1, 805 124 174. 5 1,234 199 Oxalic Acid 77. 2 2a 1, 805 124 174. 5 1, 284 196 MaleicAnhydride 2a 1. 805 124 174. 5 1, 284 196 Phthalic Anhydride 90. 8 2a 1,805 124 174. 5 l, 284 197 Cltraconic Anhyd 68. 6 2a 1, 805 124 174. 5 l,284 212 Aconitic Acid- 2a 1,805 124 174. 5 1, 234 204 Citranlie Anhyd 713a 3, 335 67. 3 98. 4 2,280 197 Diglycolic Acid 46. 1 3a 3, 335 67. 398. 4 2, 280 197 Oxalic Acid- 43. 5 3a 3, 335 67. 3 98. 4 2, 280 215Maleic Anhydride. 37. 0 3a 3, 335 67. 3 98. 4 2, 280 198 PhthalicAnhvdride 51. 5 3a 3, 335 67. 3 98. 4 2, 280 201 Oitraconic Anhyd 39. 43a 3, 335 67. 3 98. 4 2, 280 199 Aconitic Acid. 61. 0 4a 5, 62a 39. 9 663,400 200 Digl lic Acid. 31. 5 4a 5, 625 39. 9 66 3, 400 215 Oxalic Acid31.8 4a 5, 625 39. 9 66 3, 400 201 Maleic Anhydride 23. 2 4a 5, 625 39.9 66 3,400 202 Phthalic Anliydride 35. 2 4a 5, 625 39. 9 66 3, 400 205Citraconic Anhydride... 27.0 411 5, 625 39. 9 66 3, 400 199 AconiticAcid 40. 6 5a 7, 395 30. 4 51. 3 4. 370 200 Diglycolic Acid 24. 5 5a 7,395 30. 4 51.3 4, 370 200 Oxalic Acid 24. 7 5a 7. 395 30. 4 51. 3 4, 370200 Male \nliydride 18.0 5a 7, 395 30. 4 51. 3 4, 370 200 PhthalicAnhydride. 27.4 50 7, 395 30. 4 51. 3 4, 370 200 Aconitic Acid S1. 5

TABLE 3 Maximum Ex. N o. Amt. Estcrifiggg gf Water of Acid SolventSolvent cation cation o t Ester (grs.) Tenoip, (hts) (cc.)

#73, methanol 435 11 15. 6 o 429 130 1% 15. 0 554 554 1.10 1

426 128 1 3, met 522 132 l 15. 5

haiiol, Diet'nyl Carbitol.

\ solidified.

The produce for manufacturing the esters has been illustrated bypreceding examples. If for any reason reaction does not take place in ais not precipitating out.

salt such as sodium chloride or sodium sulfate Such salt should beeliminated. at least for exploration experimentae tion, and can beremoved by filtering. Everything else being equal, as the size of themolecule increases and the reactive hydroxyl radical represents asmaller fraction of the entire molecute, more difficulty is involved inobtaining complete esterification.

Even under the most carefully controlled con ditions of oxypropylationinvolving comparatively low temperature and long time of reaction thereare formed certain compounds whose composition is still obscure. Suchside reaction products can contribute a. substantial proportion of thefinal cogeneric reaction mixture. Various suggestions have been made asto the nature of these compounds, such as being cyclic polymers ofpropylene oxide, dehydration products with the appearance of a vinylradical, or isomers of propylene oxide or derivatives thereof, 1. e., ofan aldehyde, ketone, or allyl alcohol. In some instances an attempt toreact the stoichiometric amount of a polycarboxy acid with theoxypropylated derivative results in an excess of the carboxylatedreactant for the reason that apparently under conditions of reactionless reactive hydroxyl radicals are present than indicated by thehydroxyl value. Under such circumstances there is simply a residue ofthe carboxylic reactant which can be removed by filtration or, ifdesired, the esterification procedure can be repeated using anappropriately reduced ratio of carboxylic reactant.

Even the determination of the hydroxyl value by conventional procedureleaves much to be desired due either to the cogeneric materialspreviously referred to, or for that matter, the presence of anyinorganic salts or propylene oxide. Obviously this oxide should beeliminated.

The solvent employed, if any, can be removed from the finished ester bydistillation and par-' ticularly vacuum distillation. The final productsor liquids are generally pale amber, amber, to dark-reddish-amber incolor, and show moderate viscosity. They can be bleached with bleachingclays, filtering chars, and the like; However, for the purpose ofdemulsification or the like color is not a factor and decolorization isnot justified.

In the above instance I have permitted the solvents to remain present inthe final reaction mass. In other instances I have followed the sameprocedure using decalin or a mixture of decalin or benzene in the samemanner and ultimately removed all the solvents by vacuum distillation.Appearance of the final products are much the same as the polyols beforeesterification and in some instances were somewhat darker in color andhad a reddish cast and perhaps somewhat more viscous.

PART 3 In the hereto appended claims the demulsifying agent is describedas an ester obtained from a polyhydroxylated material prepared from atetramine. If one were concerned with a monohydroxylated material or adihydroxylated material one might be able to write a formula which inessence would represent the particular product. However, in a morehighly hydroxylated material the problem becomes inceasingly moredifficult for reasons which have already been indicated in connectionwith oxypropylation and which can be examined by merely considering forthe moment a monohydroxylated material.

Oxypropylation involves the same sort of variations as appear inpreparing high molal polypropylene glycols. Propylene glycol has asecondary alcoholic radical and a primary alcohol radical. Obviouslythen polypropylene glycols could be obtained, at least theoretically, inwhich two secondary alcoholic groups are united or a secondary alcoholgroup is united to a primary alcohol group, etherization being involved,of course, in each instance. Needless to say, the same situation applieswhen one has oxypropylated polyhydric materials having 4 or morehydroxyls, or the obvious equivalent.

Usually no efiort is made to differentiate between oxypropylation takingplace, for example, at the primary alcohol radical or the secondaryalcohol radical. are obtained, such as a high molal polypropylene glycolor the products obtained in the manner herein described one does notobtain a single derivative such as HO(RO) nH or (RO)nH in which n hasone and only one value, for instance, 14, 15 or 16, or the like. Rather,one obtains a cogeneric mixture of closely related or touchinghomologues. These materials invariably have high molecular weights andcannot be separated from one another by any known procedure withoutdecomoposition. The properties of such mixture represent thecontribution of the vari--;

ous individual members of the mixture. On a statistical basis, ofcourse, 11. can be appropriately specified. For practical purposes oneneed only consider the oxypropylation of a monohydric alcohol because inessence this is substantially the mechanism involved. Even in suchinstances where one is concerned with a monohydric reactant one cannotdraw a single formula and say that by following such procedure on canreadily obtain 80% or 90% or 100% of such compound. However, in the caseof at least monohydric initial reactants one can readily draw theformulas of a large number of compounds which appear in some of theprobable mixtures or can be prepared as components and mixtures whichare manufactured conventiona ly.

Simply by way of illustration reference is made to the copendingapplication of De Groote, Wirtel and Pettingill, Serial No. 109,791,filed August 11, 134? (now Patent 2,549,434, granted April 17, 1 5

However, momentarily referring again to a monohydric initial reactant itis obvious that if one selects any such simple hydroxylated compound andsubjects such compound to oxyalkylation, such as oxyethylations, oroxypropylation,

it becomes obvious that one is really producing a polymer of thealkylene oxides except for the terminal group. This is particularly truewhere the amount of oxide added is comparatively large, for instance,10, 20, 30, 40, or 50 units. If such compound is subjected tooxyethylation so as to introduce 30 units of ethylene oxide, it is wellknown that one does not obtain a single constituent which, for the sakeof convenience, may

be indicated as 'RO(C2H4O)30OH. Instead, one obtains a cogeneric mixtureof closely related homologues, in Which the formula may be shown as thefollowing, RO(C2I-I4O) 11H, wherein n, as far as the statistical averagegoes, is 30, but the individual members present in significant amountmay vary from instances where n has a value of 25, and perhaps less, toa point Where n may represent 35 or more. Such mixture is, as stated, acogeneric closely related series of touching homologous compounds.Considerable investigation has been made in regard to the distributionActually, when such products.

19 curves for linear polymers. Attention is directed to the articleentitled Fundamental principles of condensaticn polymerization, byFlory, which appeared in Chemical Review, volume 39, No. 1, e 3

Unfortunately, as has been pointed'out by Flory and other investigators,there is no satisfactory method, based on either experimental ormathematicalexamination, of indicating the exact proportion of thevarious members of touching homologous series which appear in cogenericcondensation products of the kind described. This means that from thepractical standpoint, i. e., the ability to describe how to make theproduct under consideration and how to repeat such production time aftertime without difficulty, it is necessary to resort to some other methodof description, or else consider the value of n, in formulass'uch asthose which have appeared previouslyand which appear in the'claims, asrepresenting both individual constituents in which n has a singledefinite value, and also with the understanding that n represents theaverage statistical value based on the'assumption of completeness ofreaction.

This may be illustrated as follows: Assume that in any particularexample themolal ratio of propylene oxide per hydroxyl is 15 to 1. Inageneric formula 15 to 1 could be 10, 20, or some other amount andindicated by 12. Referring to this specific case actually one obtainsproducts in which n probably varies from 10 to 20, perhaps even further.The average value, however, is 15, assuming, as previously stated, thatthe reaction is complete. The product described by the formula is bestdescribed also in terms of method of manufacture.

The significant fact in regard to the oxypropylated polyamines hereindescribed is that in the initial stage they are substantially allwater-soluble, for instance, up to a molecular weight of 2,500 orthereabouts. Actually, such molecular weight represents a mixture ofsome higher molecular weight materials and some lower molecular weightmaterials. The higher ones are probably water-insoluble. The product maytend to emulsify or disperse somewhat because some of the constituents,being a cogeneric mixture, are water-soluble but the bulk are insoluble.Thus one gets emulsifiability or dispersibility as noted. Such productsare invariably xylene-soluble regardless of whether the originalreactants were or not. Reference is made to what has been saidpreviously in regard to kerosene-solubility. For example, when thetheoretical molecular weight gets somewhere past 4,000 or atapproximately 5,000 the product is kerosene-soluble and waterinsoluble.These kerosene-soluble oxyalkylation products are most desirable forpreparing the esters. I have prepared hydroxylat'ed compounds not onlyup to the theoretical molecular weight shown previously, 1. e., about8,000 but some which were much higher. I have prepared them, not onlyfrom tetraethylenepentamihe, but also from oxyethylated or oxybutylatedderivatives previously referred to. The exact composition is open toquestion for reasons which are common to all oxyalkylation. It isinteresting to note, however, that the molecular weights based onhydroxyl determinations at this point were considerably less, in theneighborhood of a third or a fourth of the value at maximum point.Referring again to previous data it is to be noted, however, that overthe range shown of kerosene-solubility the hydroxyl molecular weight hasinvariably stayed 20- at two thirds or five-eighths of the theoreticalmolecular weight.

It becomes obvious when carboxylic esters are prepared from such highmolecular weight materials that the ultimate esterification productagain must be a cogeneric mixture. Likewise, it is obvious that thecontribution to the total molecular weight made by the polycarboxy acidis small. By the same token one would expect the effectiveness of thedemulsifier to be comparable to the unesterified hydroxylated material.Remarkably enough, inmanyihstances the product is distinctly better.

PART 4 Conventional demulsifying agents employed in the treatment of oilfield emulsions are used as such, or after dilution with any suitablsolvent, such as water, petroleum hydrocarbons, such as benzene,toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols,particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol,denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octylalcohol, etc., may be employed as diluents. Miscellaneous solvents suchas pine oil, carbon tetrachloride, sulfur dioxide extract obtained inthe refining of petroleum, etc., may be employed as diluents. Similarly,the material or materials employed as the demulsifying agent of myprocess may be admixed with one or more of the solvents customarily usedin connection with conventional demulsifying agents. Moreover, saidmaterial or materials may be used alone or in admixture with othersuitable wellknown classes of demulsifying agents.

It is well known that conventional demulsifying agents may be used in awater-soluble form, or in an oil-soluble form, or in a form exhibitingboth oiland water-solubility. Sometimes they may be used in a form whichexhibits relatively limited oil-solubility. However, since such reagentsare frequently used in a ratio of 1 to 10,000 or 1 to 20,000, or 1 to30,000, or even 1 to 40,000, or 1 to 50,000 as in desalting practice,such an apparent insolubility in oil and water is not significantbecause said reagents undoubtedly have solubility within suchconcentrations. This same fact is true in regard to the material ormaterials employed as the demulsifying agent of my process.

In practicing my 'process'for resolving petroleum emulsions afterwater-in-oil type, a treating agent or demulsifying agent of the kindabove described is brought into contact with or caused to act upon theemulsion to be treatedjin any of the various apparatuses now generallyused to resolve or break petroleum emulsions with a chemical reagent,the above procedure being used alone or in combination'with otherdemulsifying procedure, such as the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in atank and conduct a batch treatment type of demulsification procedure torecover clean oil. In this'procedure the emulsion is admixed with thedemulsifier, for example by agitating the tank of emulsion and slowlydripping demulsifier into the emulsion. In some cases mixing is achievedby heating the emulsion while dripping in the demulsifier, dependingupon the convection currents in the emulsion to produce satisfactoryadmixture. In a third modification of this type of treatment, acirculating pump withdraws emulsion from, e. g., the bottom of the tank,and reintroduces it into 21 the top of the tank, the demulsifier beingadded, for example, at the suction side of said circulating pump.

In a second type of treating procedure, the demulsifier is introducedinto the well fiuids at the well-head or at some point between thewell-head and the final oil storage tank, by means of an adjustableproportioning mechanism or proportioning pump. Ordinarily the fiow offluids through the subsequent lines and fittings suffices to produce thedesired degree of mixingof demulsifier and emulsion, although in someinstances additional mixing devices may be introduced into the flowsystem. In this general procedure, the system may include variousmechanical devices for withdrawing free water, separating entrainedwater, or accomplishing quiescent settling of the chemicalized emulsion.Heating devices may likewise be incorporated in any of the treatingprocedures described herein.

A third type of application (down-the-hole) of demulsifier to emulsionis to introduce the demulsifier either periodically or continuously indiluted or undiluted form into the well and to allow it to come to thesurface with the well fluids, and then to fiow the chemicalized emulsionthrough any desirable surface equipment, such as employed in the othertreating procedures. This particular type of application is decidedlyuseful when the demulsifier is used in connection with acidification ofcalcareous oilbearing strata, especially if suspended in or-dissolved inthe acid employed for acidification.

In all cases, it will be apparent from the foregoing description, thebroad process consists simply in introducing a relatively smallproportion of demulsifier into a relatively large proportion ofemulsion, admixing the chemical and emulsion either through natural flowor through special apparatus, with or without the application of heat,and allowing the mixture to stand quiescent until the undesirable watercontent of the emulsion separates and settles from the mass.

The following is a typical installation.

A reservoir to hold the demulsifier of the kind described (diluted orundiluted) is placed at the well-head where the effluent liquids leavethe well. This reservoir or container, which may vary from gallons to 50gallons for convenience, is connected to a proportioning pump whichinjects the demulsifier drop-wise into the fluids leaving the well. Suchchemicalized fiuids pass through the fiowline into a settling tank. Thesettling tank consists of a tank of any convenient size, for instance,one which will hold amounts of fiuid produced in 4 to 24 hours (500barrels to 2000 barrels capacity), and in which there is a perpendicularconduit from the top of the tank to almost the very bottom so as topermit the incoming fluids to pass from the top of the settling tank tothe bottom, so that such incoming fluids do not disturb stratificationwhich takes place during the course of demulsification. The settlingtank has two outlets, one being below the water level to drain ofi thewater resulting from demulsification or accompanying the emulsion asfree water, the other being an oil outlet at the top to permit thepassage of dehydrated oil to a second tank, being a storage tank, whichholds pipeline or dehydrated oil. If desired, the conduit or pipe whichserves to carry the fluids from the well to the settling tank mayinclude a section of pipe with baffles to serve as a mixer, to insurethorough distribution of the demulsifier throughout the fluids, or aheater for raising the temperature of the fluids to some convenienttemperature, for instance, to F., for both heater and mixer.

Demulsification procedure is started by simply setting the pump so as tofeed a comparatively large ratio of demulsifier, for instance, 1:5,000.As soon as a complete "break or satisfactory demulsification isobtained, the pump is regulated until experience shows that the amountof demulsifier being added is just sufficient to produce clean ordehydrated oil. The amount being fed at such stage is usually l:l0,000,1:15,000, 1 :20,000, or the like.

In many instances the oxyalkylated products herein specified asdemulsifiers can be conveniently used without dilution. However, aspreviously noted, they may be diluted as desired with any suitablesolvent. For instance, by mixing (5 parts by weight of the product ofExample 26b with 15 parts by weight of xylene and 10 parts by weight ofisopropyl alcohol, an excellent demulsifier is obtained. Selection ofthe solvent will vary, depending upon the solubility characteristics ofthe oxyalkylated product, and of course will be dictated in part byeconomic considerations, i. e., cost.

As noted above, the products herein described may be used not only indiluted form, but also.

may be used admixed with some other chemical demulsifier. A mixturewhich illustrates such combination is the following:

oxyalkylated derivative, for example, the product of Example 26b, 20%

A cyclohexylamine salt of a polypropylated naphthalene mono-sulfonicacid, 24%;

An ammonium salt of a polypropylated naphthalene mono-sulfonic acid, 24

A sodium salt of oil-soluble mahogany petroleum sulfonic acid, 12% 15Ahigh-boiling aromatic petroleum solvent,

Isopropyl alcohol, 5

The above proportions are all weight percents.

Having thus described my invention, what I claim as new and desire toobtain by Letters Patent, is:

1. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being a cogeneric mixture selected from the class consisting ofacidic fractional esters, acidic ester salts, and acidic amidoderivatives obtained by reaction between (A) a polycarboxy acid, and (B)high molal oxypropylation derivatives of monomeric tetramino compounds,with the proviso that (a) the initial tetramino reactant be free fromany radical having at least 8 uninterrupted carbon atoms; (27) theinitial tetramino reactant have a molecu-' lar weight of not over 800and at least a plurality of reactive hydrogen atoms; (0) the initialtetramino reactant must be water-soluble; (d) the.

end product on a statistical basis; ('1') the preceding provisos arebased on the assumption of complete reaction involving the propyleneoxide and initial tetramino reactant; (7') the nitrogen atoms are linkedby an ethylene chain, and with the final proviso that the ratio of (A)to (B) be one mole of (A) for each reactive hydrogen atom present in (B)2. A process for breaking petroleum emulsions of thewater-in-oil typecharacterized bysubj'ecting the emulsion tothe action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being a cogeneric mixture selected from the class consisting ofacidic fractional esters, acidic ester salts, and acidicamidoderiv'atives obtained by reactionbetween (A) a polycarboxy acid'and(B) high molal oxypropylation derivatives of monomeric tetraminocompounds, with the proviso that (a) the initial tetramino reactant befree from any radical having at least 8 uninterrupted carbon atoms; (1))the-initial tetramino reactant have a molecular weight of not over 800and at least a plurality of reactive hydrogen atoms; the initialtetramino reactant must be water-soluble; (-d) the oxypropylation endproduct must be water-insoluble, and kerosene-soluble; (e)the-oxypropylation end product be Within the molecular weight range of.2500 to 30,000 on an average statistical basis; (f) the solubilitycharacteristics of the oxypropylation end product in respect to waterand kerosene must be substantially the result of the oxypropylationstep; (9) the ratio of propyl ene oxide per initial reactivehydrogen-atom must be within the range of 7 to 70; (h) the initialtetramino reactant must represent not more-than 20% by weight ofthe'oxypropylation end product on a statistical basis; (2') thepreceding provisos are based on the assumption of complete reactioninvolving the propylene oxide and initial tetramino reactant; (7') thenitrogen atoms are linked by an ethylene chain; at least one of thenitrogen atoms be basic, and with the final proviso that the ratio of(A) to (B) be one mole of (A) for each reactive hydrogen atom present in(B).

3. A process for breaking petroleum emulsions of 'the Water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being a cogeneric mixture selected from the class consisting ofacidic fractional esters, acidic ester salts, and acidic amidoderivatives obtained by reaction between (A) a polycarboxy acid and (B)high molal oxypropylation derivatives of monomeric tetramino compounds,with the proviso that (a) the initial tetramino reactant be free fromany radical having at least 8 uninterrupted carbon atoms; (1)) theinitial tetramino reactant have a molecular weight of not over 800 andat least a plurality of reactive hydrogen atoms; (0) the initialtetramino reactant must be water-soluble; (cl) the oxypropylation endproduct must be Water-insoluble, and kerosene-soluble; (e) theoxypropylation end product be within the molecular weight range of 2500to 30,000 on an average statistical basis; (7) the solubilitycharacteristics of the oxypropylation end product in respect to waterand kerosene must be substantially the result of the oxypropylationstep; (9) the ratio of propylene oxide per initial reactive hydrogenatom must be within the range of 7 to 70; (h) the initial tetraminoreactant must represent not more than by-weight-of the oxypropylationend product on a statistical basis; (1') the preceding provisos arebased on the assumption of complete reaction involving the propyleneoxide and initial tetramino reactant; (1) thenitrogen atoms are linkedby an ethylene chain; that at least two nitrogen atoms be basic; andwith the final proviso that the ratio of (A) to (B) be one mole of (A)for each reactive hydrogen atom present in '(B).

4. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being a cogeneric mixture selected from the class consisting ofacidic fractional esters, acidic ester salts, and acidic amidoderivatives obtained by reaction between (A) a polycarboxy acid freefrom any radical having more than 8 uninterrupted carbon atoms in asingle group, and (3) high molal oxypropylatio'n derivatives ofmonomeric tetramino compounds, with the proviso that (a) the initialtetraminoreactant be free from any'radical having at least 8uninterrupted carbon atoms; (1)) the initial tetramino reactant havea'molecular weight of not over 800 and at least a plurality of reactivehydrogen atoms; (0) the initial tetramino reactant must be water-soluble; (d) the oxypropylation end product must be water-insoluble,and kerosene-soluble; (e) the oxypropylation end product be Within themolecular weight range-of 2500 to 30,000 on an'average statisticalbasis; (f) the solubility characteristics of. the

oxypropylation end product in respect to water and kerosene must besubstantially the resultof the oxypropylation step; (9) 'the ratio ofpropylene oxide per initial reactive hydrogen atom must be within therange of 7 to 70; (h) the initial tetramino reactant must represent notmore than 20% by weight of the oxypropylation end. product on astatistical basis; (2') the preceding provisos are based on theassumption of complete reaction involving the propylene oxide andinitial tetramino reactant; (9) the nitrogen atoms are linked by anethylene chain; (is) that at least two nitrogen atoms be basic; and withthe final proviso that the ratioof (A) to (B) be one mole of (A) foreach reactive hydrogen atom present in (B).

5. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being a cogeneric mixture selected from the class consis'tingof acidic fractional esters, acidic ester salts, and acidic amidoderivatives obtained by reaction between (A) a dicarboxy acid free fromany radical having more than 8 uninterrupted carbon atoms in a singlegroup, and (B) high molal oxypropylation derivatives of monomerictetramino compounds, with the proviso that-(a) the initial tetraminoreactant be free from any radical having at least 8 uninterrupted carbonatoms; (1)) the initial tetramino reactant have a molecular weight ofnot over 800 and at least a plurality of reactive hydrogen atoms; (0)the initial tetramino reactant must be water-soluble; (d) theoxypropylation end product must be water-insoluble, andkerosene-soluble; (e) the oxypropylation end product be within themolecular weight range of 2500 to 30,000 on an average statisticalbasis; (1) the solubility characteristics of the oxypropylation endproduct in respect to water and kerosene must be substantially theresult of the oxypropylation step; (g) the ratio of propylene oxide perinitial reactive hydrogen atom must be within the range of 7 to 70; (h)the initial tetramino reactant must represent not more than 20% byweight of the oxypropylation end product on a statistical basis; (2')the preceding provisos are based on the assumption of complete reactioninvolving the propylene oxide and initial tetramino reactant; (:i) thenitrogen atoms are linked by an ethylene chain; (k) that at least twonitrogen atoms be basic; and with the final proviso that the ratio of(A) to (B) be one mole of (A) for each reactive hydrogen atom present in(B).

6. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being a cogeneric mixture selected from the class consisting ofacidic fractional esters, acidic ester salts, and acidic amidoderivatives obtained by reaction between (A) a dicarboxy acid free fromany radical having more than 8 uninterrupted carbon atoms in a singlegroup, and (B) high molal oxypropylation derivatives oftriethylenetetramine, with the proviso that (a) the oxypropylation endproduct must be water-insoluble and kerosene-soluble; (b) theoxypropylation end product be within the molecular weight range 'of 2500to 30,000 on an average statistical basis;

(0) the solubility characteristics of the oxypropylation end product inrespect to water and kerosene must be substantially the result of theoxypropylation step; (d) the ratio of propylene oxide per initialreactive hydrogen atom must be within the range of '7 to 70; (e) theinitial tetramino reactant must represent not more than 20% by weight ofthe oxypropylation end product on a statistical basis; (1) the precedingprovisos are based on the assumption of complete reaction involving thepropylene oxide and initial tetramino reactant; and with the finalproviso that the ratio of (A) to (B) be one mole of (A) for eachreactive hydrogen atom present in (B).

7. The process of claim 6 wherein the dicarboxy acid is diglycollicacid.

8. The process of claim 6 wherein the dicarboxy acid is maleic acid.

9. The process of claim 6 wherein the dicarboxy acid is phthalic acid.

10. The process of claim 6 wherein the dicarboxy acid is citraconicacid.

11. The process of claim 6 wherein the dicarboxy acid is succinic acid.

his MELVIN DE GROOTE.

mark Witnesses to mark:

W. C. ADAMS, I. S. DE GROOTE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,243,329 De Groote et a1 May 27,1941 2,295,169 De Groote et al Sept. 8, 1942 2,562,878 Blair Aug. '7,1951

1. A PROCESS FOR BREADKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIER INCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETIC PRODUCTS BEING A COGENERIC MIXTURE SELECTED FROM THE CLASS CONSISTING OF ACIDIC FRACTIONAL ESTERS, ACIDIC ESTER SALTS, AND ACIDIC AMIDO DERIVATIVES OBTAINED BY REACTION BETWEEN (A) A POLYCARBOXY ACID, AND (B) HIGH MOLAL OXYPROPYLATION DERIVATIVES OF MONOMERIC TETRAMINO COMPOUNDS, WITH THE PROVISO THAT (A) THE INITIAL TETRAMINO REACTANT BE FREE FROM ANY RADICAL HAVING AT LEAST 8 UNINTERRUPTED CARBON ATOMS; (B) THE INITIAL TETRAMINO REACTANT HAVE A MOLECULAR WEIGHT OF NOT OVER 800 AND AT LEAST A PLURALITY OF REACTIVE HYDROGEN ATOMS; (C) THE INITIAL TETRAMINO REACTANT MUST BE WATER-SOLUBLE; (D) THE OXYPROPYLATION END PRODUCT MUST BE WATERINSOLUBLE, AND KEROSENE SOLUBLE; (E) THE OXYPROPYLATION END PRODUCT BE WITHIN THE MOLECULAR WEIGHT RANGE OF 2500 TO 30,000 ON AN AVERAGE STATISTICAL BASIS; (F) THE SOLUBILITY CHARACTERISTICS OF THE OXYPROPYLATION END PRODUCT IN RESPECT TO WATER AND KEROSENE MUST BE SUBSTANTIALLY THE RESULT OF THE OXYPROPYLATION STEP; (G) THE RATIO OF PROPYLENE OXIDE PER INITIAL REACTIVE HYDROGEN ATOM MUST BE WITHIN THE RANGE OF 7 TO 70; (H) THE INITIAL TETRAMINO REACTANT MUST REPRESENT NOT MORE THAN 20% BY WEIGHT OF THE OXYPROPYLATION END PRODUCT ON A STATISTICAL BASIS; (I) THE PRECEDING PROVISOS ARE BASED ON THE ASSUMPTION OF COMPLETE REACTION INVOLVING THE PROPYLENE OXIDE AND INITIAL TETRAMINO REACTANT; (J) THE NITROGEN ATOMS ARE LINKED BY AN ETHYLENE CHAIN, AND WITH THE FINAL PROVISO THAT THE RATIO OF (A) TO (B) BE ONE MOLE OF (A) FOR EACH REACTIVE HYDROGEN ATOM PRESENT IN (B). 